diff mbox series

[FFmpeg-devel,v18,06/10] avcodec/evc_decoder: Provided support for EVC decoder

Message ID 20230328135007.1765-1-d.kozinski@samsung.com
State New
Headers show
Series [FFmpeg-devel,v18,01/10] avcodec/evc: MPEG-5 EVC codec registration | expand

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Commit Message

Dawid Kozinski March 28, 2023, 1:50 p.m. UTC 
- Added EVC decoder wrapper
- Changes in project configuration file and libavcodec Makefile
- Added documentation for xevd wrapper

Signed-off-by: Dawid Kozinski <d.kozinski@samsung.com>
---
 configure                 |   4 +
 doc/decoders.texi         |  24 ++
 doc/general_contents.texi |  10 +-
 libavcodec/Makefile       |   1 +
 libavcodec/allcodecs.c    |   1 +
 libavcodec/libxevd.c      | 488 ++++++++++++++++++++++++++++++++++++++
 6 files changed, 527 insertions(+), 1 deletion(-)
 create mode 100644 libavcodec/libxevd.c

Comments

James Almer March 29, 2023, 12:16 p.m. UTC | #1 
On 3/28/2023 10:50 AM, Dawid Kozinski wrote:
> +static int libxevd_receive_frame(AVCodecContext *avctx, AVFrame *frame)
> +{
> +    XevdContext *xectx = NULL;
> +    AVPacket *pkt = NULL;
> +    XEVD_IMGB *imgb = NULL;
> +
> +    int xevd_ret = 0;
> +    int ret = 0;
> +
> +    xectx = avctx->priv_data;
> +
> +    pkt = av_packet_alloc();
> +    if (!pkt)
> +        return AVERROR(ENOMEM);

This is very inefficient. Just keep an AVPacket in the XevdContext, 
allocating it on init(), unrefing it after being used in this function, 
and freeing it on close().

> +
> +    // obtain input data
> +    ret = ff_decode_get_packet(avctx, pkt);
> +    if (ret < 0 && ret != AVERROR_EOF) {
> +        av_packet_free(&pkt);
> +        return ret;
> +    } else if(ret == AVERROR_EOF && xectx->draining_mode == 0) { // End of stream situations. Enter draining mode
> +
> +        frame = NULL;
> +        xectx->draining_mode = 1;
> +
> +        av_packet_free(&pkt);
> +
> +        return AVERROR_EOF;

By returning EOF here you're effectively ending the decoding process. No 
draining is taking place. This function is not going to be called again 
for the xectx->draining_mode == 1 to take effect.

> +    }
> +
> +    if (pkt->size > 0) {
> +        int bs_read_pos = 0;
> +        XEVD_STAT stat;
> +        XEVD_BITB bitb;
> +        int nalu_size;
> +
> +        imgb = NULL;
> +
> +        while(pkt->size > (bs_read_pos + XEVD_NAL_UNIT_LENGTH_BYTE)) {
> +            memset(&stat, 0, sizeof(XEVD_STAT));
> +
> +            nalu_size = read_nal_unit_length(pkt->data + bs_read_pos, XEVD_NAL_UNIT_LENGTH_BYTE, avctx);
> +            if (nalu_size == 0) {
> +                av_log(avctx, AV_LOG_ERROR, "Invalid bitstream\n");
> +                av_packet_free(&pkt);
> +                ret = AVERROR_INVALIDDATA;
> +                return ret;
> +            }
> +            bs_read_pos += XEVD_NAL_UNIT_LENGTH_BYTE;
> +
> +            bitb.addr = pkt->data + bs_read_pos;
> +            bitb.ssize = nalu_size;
> +
> +            /* main decoding block */
> +            xevd_ret = xevd_decode(xectx->id, &bitb, &stat);
> +            if (XEVD_FAILED(xevd_ret)) {
> +                av_log(avctx, AV_LOG_ERROR, "Failed to decode bitstream\n");
> +                av_packet_free(&pkt);
> +                ret = AVERROR_EXTERNAL;
> +                return ret;
> +            }
> +
> +            bs_read_pos += nalu_size;
> +
> +            if (stat.nalu_type == XEVD_NUT_SPS) { // EVC stream parameters changed
> +                if ((ret = export_stream_params(xectx, avctx)) != 0) {
> +                    av_log(avctx, AV_LOG_ERROR, "Failed to export stream params\n");
> +                    av_packet_free(&pkt);
> +                    return ret;
> +                }
> +            }
> +            if (stat.read != nalu_size)
> +                av_log(avctx, AV_LOG_INFO, "Different reading of bitstream (in:%d,read:%d)\n,", nalu_size, stat.read);
> +            if (stat.fnum >= 0) {
> +                // already has a decoded image
> +                if (imgb) {
> +                    // xevd_pull uses pool of objects of type XEVD_IMGB.
> +                    // The pool size is equal MAX_PB_SIZE (26), so release object when it is no more needed
> +                    imgb->release(imgb);
> +                    imgb = NULL;

Aren't you dropping an image you should be propagating instead with this?

> +                }
> +                xevd_ret = xevd_pull(xectx->id, &imgb);
> +                if (XEVD_FAILED(xevd_ret)) {
> +                    av_log(avctx, AV_LOG_ERROR, "Failed to pull the decoded image (xevd error code: %d, frame#=%d)\n", xevd_ret, stat.fnum);
> +                    ret = AVERROR_EXTERNAL;
> +                    av_packet_free(&pkt);
> +
> +                    return ret;
> +                }  else if (xevd_ret == XEVD_OK_FRM_DELAYED) {
> +                    if (imgb) {
> +                        // xevd_pull uses pool of objects of type XEVD_IMGB.
> +                        // The pool size is equal MAX_PB_SIZE (26), so release object when it is no more needed
> +                        imgb->release(imgb);
> +                        imgb = NULL;

Can an image be returned when xevd_ret == XEVD_OK_FRM_DELAYED? If so, 
shouldn't you propagate it?

> +                    }
> +                    av_packet_free(&pkt);
> +
> +                    return AVERROR(EAGAIN);
> +                }
> +                if (imgb) { // got frame
> +                    int ret = libxevd_image_copy(avctx, imgb, frame);
> +                    if(ret < 0) {
> +                        av_log(avctx, AV_LOG_ERROR, "Image copying error\n");
> +                        if (imgb) {
> +                            imgb->release(imgb);
> +                            imgb = NULL;
> +                        }
> +                        av_packet_free(&pkt);
> +
> +                        return ret;
> +                    }
> +
> +                    // use ff_decode_frame_props() to fill frame properties
> +                    ret = ff_decode_frame_props(avctx, frame);
> +                    if (ret < 0) {
> +                        if (imgb) {
> +                            imgb->release(imgb);
> +                            imgb = NULL;
> +                        }
> +                        av_packet_free(&pkt);
> +                        av_frame_unref(frame);
> +
> +                        return ret;
> +                    }
> +                    // match timestamps and packet size
> +                    ret = ff_decode_frame_props_from_pkt(avctx, frame, pkt);
> +                    pkt->opaque = NULL;

You copy-pasted this from libdav1d.c without knowing what it's doing.
You don't need to clear opaque, and you don't need to call 
ff_decode_frame_props_from_pkt() with the current packet when 
ff_decode_frame_props() is already doing it for you. The former function 
is only needed when you need props from a packet other than the last one 
fed to the decoder.

> +                    if (ret < 0) {
> +                        if (imgb) {
> +                            imgb->release(imgb);
> +                            imgb = NULL;
> +                        }
> +                        av_packet_free(&pkt);
> +                        av_frame_unref(frame);
> +
> +                        return ret;
> +                    }
> +
> +                    frame->pkt_dts = pkt->dts;
> +
> +                    // xevd_pull uses pool of objects of type XEVD_IMGB.
> +                    // The pool size is equal MAX_PB_SIZE (26), so release object when it is no more needed
> +                    imgb->release(imgb);
> +                    imgb = NULL;
> +
> +                    return 0;
> +                } else
> +                    return  AVERROR(EAGAIN);
> +            }
> +        }
> +    } else { // decoder draining mode handling
> +        xevd_ret = xevd_pull(xectx->id, &imgb);
> +        if (xevd_ret == XEVD_ERR_UNEXPECTED)   // draining process completed
> +            return AVERROR_EOF;
> +        else if (XEVD_FAILED(xevd_ret)) {
> +            av_log(avctx, AV_LOG_ERROR, "Failed to pull the decoded image (xevd error code: %d)\n", xevd_ret);
> +
> +            if (imgb) {
> +                imgb->release(imgb);
> +                imgb = NULL;
> +            }
> +
> +            av_packet_free(&pkt);
> +
> +            return AVERROR_EXTERNAL;
> +        }
> +        if (imgb) { // got frame
> +            int ret = libxevd_image_copy(avctx, imgb, frame);
> +            if(ret < 0) {
> +                if (imgb) {
> +                    imgb->release(imgb);
> +                    imgb = NULL;
> +                }
> +                av_packet_free(&pkt);
> +            }
> +
> +            frame->pkt_dts = pkt->dts;
> +
> +            // xevd_pull uses pool of objects of type XEVD_IMGB.
> +            // The pool size is equal MAX_PB_SIZE (26), so release object when it is no more needed
> +            imgb->release(imgb);
> +            imgb = NULL;
> +
> +            return 0;
> +        }
> +        return AVERROR_EOF;
> +    }
> +    return ret;
> +}
Dawid Kozinski March 30, 2023, 10:09 a.m. UTC | #2 
> -----Original Message-----
> From: ffmpeg-devel <ffmpeg-devel-bounces@ffmpeg.org> On Behalf Of James
> Almer
> Sent: środa, 29 marca 2023 14:17
> To: ffmpeg-devel@ffmpeg.org
> Subject: Re: [FFmpeg-devel] [PATCH v18 06/10] avcodec/evc_decoder:
Provided
> support for EVC decoder
> 
> On 3/28/2023 10:50 AM, Dawid Kozinski wrote:
> > +static int libxevd_receive_frame(AVCodecContext *avctx, AVFrame
> > +*frame) {
> > +    XevdContext *xectx = NULL;
> > +    AVPacket *pkt = NULL;
> > +    XEVD_IMGB *imgb = NULL;
> > +
> > +    int xevd_ret = 0;
> > +    int ret = 0;
> > +
> > +    xectx = avctx->priv_data;
> > +
> > +    pkt = av_packet_alloc();
> > +    if (!pkt)
> > +        return AVERROR(ENOMEM);
> 
> This is very inefficient. Just keep an AVPacket in the XevdContext,
allocating it on
> init(), unrefing it after being used in this function, and freeing it on
close().
> 
> > +
> > +    // obtain input data
> > +    ret = ff_decode_get_packet(avctx, pkt);
> > +    if (ret < 0 && ret != AVERROR_EOF) {
> > +        av_packet_free(&pkt);
> > +        return ret;
> > +    } else if(ret == AVERROR_EOF && xectx->draining_mode == 0) { //
> > + End of stream situations. Enter draining mode
> > +
> > +        frame = NULL;
> > +        xectx->draining_mode = 1;
> > +
> > +        av_packet_free(&pkt);
> > +
> > +        return AVERROR_EOF;
> 
> By returning EOF here you're effectively ending the decoding process. No
> draining is taking place. This function is not going to be called again
for the
> xectx->draining_mode == 1 to take effect.
> 
> > +    }
> > +
> > +    if (pkt->size > 0) {
> > +        int bs_read_pos = 0;
> > +        XEVD_STAT stat;
> > +        XEVD_BITB bitb;
> > +        int nalu_size;
> > +
> > +        imgb = NULL;
> > +
> > +        while(pkt->size > (bs_read_pos + XEVD_NAL_UNIT_LENGTH_BYTE)) {
> > +            memset(&stat, 0, sizeof(XEVD_STAT));
> > +
> > +            nalu_size = read_nal_unit_length(pkt->data + bs_read_pos,
> XEVD_NAL_UNIT_LENGTH_BYTE, avctx);
> > +            if (nalu_size == 0) {
> > +                av_log(avctx, AV_LOG_ERROR, "Invalid bitstream\n");
> > +                av_packet_free(&pkt);
> > +                ret = AVERROR_INVALIDDATA;
> > +                return ret;
> > +            }
> > +            bs_read_pos += XEVD_NAL_UNIT_LENGTH_BYTE;
> > +
> > +            bitb.addr = pkt->data + bs_read_pos;
> > +            bitb.ssize = nalu_size;
> > +
> > +            /* main decoding block */
> > +            xevd_ret = xevd_decode(xectx->id, &bitb, &stat);
> > +            if (XEVD_FAILED(xevd_ret)) {
> > +                av_log(avctx, AV_LOG_ERROR, "Failed to decode
bitstream\n");
> > +                av_packet_free(&pkt);
> > +                ret = AVERROR_EXTERNAL;
> > +                return ret;
> > +            }
> > +
> > +            bs_read_pos += nalu_size;
> > +
> > +            if (stat.nalu_type == XEVD_NUT_SPS) { // EVC stream
parameters
> changed
> > +                if ((ret = export_stream_params(xectx, avctx)) != 0) {
> > +                    av_log(avctx, AV_LOG_ERROR, "Failed to export
stream
> params\n");
> > +                    av_packet_free(&pkt);
> > +                    return ret;
> > +                }
> > +            }
> > +            if (stat.read != nalu_size)
> > +                av_log(avctx, AV_LOG_INFO, "Different reading of
bitstream
> (in:%d,read:%d)\n,", nalu_size, stat.read);
> > +            if (stat.fnum >= 0) {
> > +                // already has a decoded image
> > +                if (imgb) {
> > +                    // xevd_pull uses pool of objects of type
XEVD_IMGB.
> > +                    // The pool size is equal MAX_PB_SIZE (26), so
release object when
> it is no more needed
> > +                    imgb->release(imgb);
> > +                    imgb = NULL;
> 
> Aren't you dropping an image you should be propagating instead with this?
> 
> > +                }
> > +                xevd_ret = xevd_pull(xectx->id, &imgb);
> > +                if (XEVD_FAILED(xevd_ret)) {
> > +                    av_log(avctx, AV_LOG_ERROR, "Failed to pull the
decoded image
> (xevd error code: %d, frame#=%d)\n", xevd_ret, stat.fnum);
> > +                    ret = AVERROR_EXTERNAL;
> > +                    av_packet_free(&pkt);
> > +
> > +                    return ret;
> > +                }  else if (xevd_ret == XEVD_OK_FRM_DELAYED) {
> > +                    if (imgb) {
> > +                        // xevd_pull uses pool of objects of type
XEVD_IMGB.
> > +                        // The pool size is equal MAX_PB_SIZE (26), so
release object
> when it is no more needed
> > +                        imgb->release(imgb);
> > +                        imgb = NULL;
> 
> Can an image be returned when xevd_ret == XEVD_OK_FRM_DELAYED? If so,
> shouldn't you propagate it?
> 
> > +                    }
> > +                    av_packet_free(&pkt);
> > +
> > +                    return AVERROR(EAGAIN);
> > +                }
> > +                if (imgb) { // got frame
> > +                    int ret = libxevd_image_copy(avctx, imgb, frame);
> > +                    if(ret < 0) {
> > +                        av_log(avctx, AV_LOG_ERROR, "Image copying
error\n");
> > +                        if (imgb) {
> > +                            imgb->release(imgb);
> > +                            imgb = NULL;
> > +                        }
> > +                        av_packet_free(&pkt);
> > +
> > +                        return ret;
> > +                    }
> > +
> > +                    // use ff_decode_frame_props() to fill frame
properties
> > +                    ret = ff_decode_frame_props(avctx, frame);
> > +                    if (ret < 0) {
> > +                        if (imgb) {
> > +                            imgb->release(imgb);
> > +                            imgb = NULL;
> > +                        }
> > +                        av_packet_free(&pkt);
> > +                        av_frame_unref(frame);
> > +
> > +                        return ret;
> > +                    }
> > +                    // match timestamps and packet size
> > +                    ret = ff_decode_frame_props_from_pkt(avctx, frame,
pkt);
> > +                    pkt->opaque = NULL;
> 
> You copy-pasted this from libdav1d.c without knowing what it's doing.
> You don't need to clear opaque, and you don't need to call
> ff_decode_frame_props_from_pkt() with the current packet when
> ff_decode_frame_props() is already doing it for you. The former function
is only
> needed when you need props from a packet other than the last one fed to
the
> decoder.
> 
> > +                    if (ret < 0) {
> > +                        if (imgb) {
> > +                            imgb->release(imgb);
> > +                            imgb = NULL;
> > +                        }
> > +                        av_packet_free(&pkt);
> > +                        av_frame_unref(frame);
> > +
> > +                        return ret;
> > +                    }
> > +
> > +                    frame->pkt_dts = pkt->dts;
> > +
> > +                    // xevd_pull uses pool of objects of type
XEVD_IMGB.
> > +                    // The pool size is equal MAX_PB_SIZE (26), so
release object when
> it is no more needed
> > +                    imgb->release(imgb);
> > +                    imgb = NULL;
> > +
> > +                    return 0;
> > +                } else
> > +                    return  AVERROR(EAGAIN);
> > +            }
> > +        }
> > +    } else { // decoder draining mode handling
> > +        xevd_ret = xevd_pull(xectx->id, &imgb);
> > +        if (xevd_ret == XEVD_ERR_UNEXPECTED)   // draining process
completed
> > +            return AVERROR_EOF;
> > +        else if (XEVD_FAILED(xevd_ret)) {
> > +            av_log(avctx, AV_LOG_ERROR, "Failed to pull the decoded
> > + image (xevd error code: %d)\n", xevd_ret);
> > +
> > +            if (imgb) {
> > +                imgb->release(imgb);
> > +                imgb = NULL;
> > +            }
> > +
> > +            av_packet_free(&pkt);
> > +
> > +            return AVERROR_EXTERNAL;
> > +        }
> > +        if (imgb) { // got frame
> > +            int ret = libxevd_image_copy(avctx, imgb, frame);
> > +            if(ret < 0) {
> > +                if (imgb) {
> > +                    imgb->release(imgb);
> > +                    imgb = NULL;
> > +                }
> > +                av_packet_free(&pkt);
> > +            }
> > +
> > +            frame->pkt_dts = pkt->dts;
> > +
> > +            // xevd_pull uses pool of objects of type XEVD_IMGB.
> > +            // The pool size is equal MAX_PB_SIZE (26), so release
object when it is
> no more needed
> > +            imgb->release(imgb);
> > +            imgb = NULL;
> > +
> > +            return 0;
> > +        }
> > +        return AVERROR_EOF;
> > +    }
> > +    return ret;
> > +}
> ___


I'm sorry for not replying earlier but I've been experiencing an internet
connection issue since yesterday. I had an outage and no network connection.

I will make all the necessary changes in the code and upload new patches as
fast as possible.
diff mbox series

Patch

diff --git a/configure b/configure
index 4b6db91de5..0b9f1d184a 100755
--- a/configure
+++ b/configure
@@ -292,6 +292,7 @@  External library support:
   --enable-libx264         enable H.264 encoding via x264 [no]
   --enable-libx265         enable HEVC encoding via x265 [no]
   --enable-libxeve         enable EVC encoding via libxeve [no]
+  --enable-libxevd         enable EVC decoding via libxevd [no]
   --enable-libxavs         enable AVS encoding via xavs [no]
   --enable-libxavs2        enable AVS2 encoding via xavs2 [no]
   --enable-libxcb          enable X11 grabbing using XCB [autodetect]
@@ -1863,6 +1864,7 @@  EXTERNAL_LIBRARY_LIST="
     libvorbis
     libvpx
     libwebp
+    libxevd
     libxeve
     libxml2
     libzimg
@@ -3399,6 +3401,7 @@  libx265_encoder_deps="libx265"
 libx265_encoder_select="atsc_a53"
 libxavs_encoder_deps="libxavs"
 libxavs2_encoder_deps="libxavs2"
+libxevd_decoder_deps="libxevd"
 libxeve_encoder_deps="libxeve"
 libxvid_encoder_deps="libxvid"
 libzvbi_teletext_decoder_deps="libzvbi"
@@ -6738,6 +6741,7 @@  enabled libx265           && require_pkg_config libx265 x265 x265.h x265_api_get
                              require_cpp_condition libx265 x265.h "X265_BUILD >= 89"
 enabled libxavs           && require libxavs "stdint.h xavs.h" xavs_encoder_encode "-lxavs $pthreads_extralibs $libm_extralibs"
 enabled libxavs2          && require_pkg_config libxavs2 "xavs2 >= 1.3.0" "stdint.h xavs2.h" xavs2_api_get
+enabled libxevd           && require_pkg_config libxevd "xevd >= 0.4.0" "xevd.h" xevd_decode
 enabled libxeve           && require_pkg_config libxeve "xeve >= 0.4.0" "xeve.h" xeve_encode
 enabled libxvid           && require libxvid xvid.h xvid_global -lxvidcore
 enabled libzimg           && require_pkg_config libzimg "zimg >= 2.7.0" zimg.h zimg_get_api_version
diff --git a/doc/decoders.texi b/doc/decoders.texi
index 5ba85cf9b1..54720ee8b4 100644
--- a/doc/decoders.texi
+++ b/doc/decoders.texi
@@ -130,6 +130,30 @@  Set amount of frame threads to use during decoding. The default value is 0 (auto
 
 @end table
 
+@section libxevd
+
+eXtra-fast Essential Video Decoder (XEVD) MPEG-5 EVC decoder wrapper.
+
+This decoder requires the presence of the libxevd headers and library
+during configuration. You need to explicitly configure the build with
+@option{--enable-libxevd}.
+
+The xevd project website is at @url{https://github.com/mpeg5/xevd}.
+
+@subsection Options
+
+The following options are supported by the libxevd wrapper.
+The xevd-equivalent options or values are listed in parentheses for easy migration.
+
+To get a more accurate and extensive documentation of the libxevd options,
+invoke the command  @code{xevd_app --help} or consult the libxevd documentation.
+
+@table @option
+@item threads (@emph{threads})
+Force to use a specific number of threads
+
+@end table
+
 @section QSV Decoders
 
 The family of Intel QuickSync Video decoders (VC1, MPEG-2, H.264, HEVC,
diff --git a/doc/general_contents.texi b/doc/general_contents.texi
index 31f1793b9e..8e08f5ebc3 100644
--- a/doc/general_contents.texi
+++ b/doc/general_contents.texi
@@ -351,6 +351,14 @@  Go to @url{https://github.com/mpeg5/xeve} and follow the instructions for
 installing the XEVE library. Then pass @code{--enable-libxeve} to configure to
 enable it.
 
+@section eXtra-fast Essential Video Decoder (XEVD)
+
+FFmpeg can make use of the XEVD library for EVC video decoding.
+
+Go to @url{https://github.com/mpeg5/xevd} and follow the instructions for
+installing the XEVD library. Then pass @code{--enable-libxevd} to configure to
+enable it.
+
 @section ZVBI
 
 ZVBI is a VBI decoding library which can be used by FFmpeg to decode DVB
@@ -953,7 +961,7 @@  following image formats are supported:
 @item Escape 124             @tab     @tab  X
 @item Escape 130             @tab     @tab  X
 @item EVC / MPEG-5 Part 1    @tab  X  @tab  X
-    @tab encoding and decoding supported through external librariy libxeve
+    @tab encoding and decoding supported through external libraries libxeve and libxevd
 @item FFmpeg video codec #1  @tab  X  @tab  X
     @tab lossless codec (fourcc: FFV1)
 @item Flash Screen Video v1  @tab  X  @tab  X
diff --git a/libavcodec/Makefile b/libavcodec/Makefile
index 53ffdc5bbe..1c473f3beb 100644
--- a/libavcodec/Makefile
+++ b/libavcodec/Makefile
@@ -1130,6 +1130,7 @@  OBJS-$(CONFIG_LIBX264_ENCODER)            += libx264.o
 OBJS-$(CONFIG_LIBX265_ENCODER)            += libx265.o
 OBJS-$(CONFIG_LIBXAVS_ENCODER)            += libxavs.o
 OBJS-$(CONFIG_LIBXAVS2_ENCODER)           += libxavs2.o
+OBJS-$(CONFIG_LIBXEVD_DECODER)            += libxevd.o
 OBJS-$(CONFIG_LIBXEVE_ENCODER)            += libxeve.o
 OBJS-$(CONFIG_LIBXVID_ENCODER)            += libxvid.o
 OBJS-$(CONFIG_LIBZVBI_TELETEXT_DECODER)   += libzvbi-teletextdec.o ass.o
diff --git a/libavcodec/allcodecs.c b/libavcodec/allcodecs.c
index acfade1893..a55a06023e 100644
--- a/libavcodec/allcodecs.c
+++ b/libavcodec/allcodecs.c
@@ -815,6 +815,7 @@  extern LIBX264_CONST FFCodec ff_libx264_encoder;
 extern const FFCodec ff_libx264rgb_encoder;
 extern FFCodec ff_libx265_encoder;
 extern const FFCodec ff_libxeve_encoder;
+extern const FFCodec ff_libxevd_decoder;
 extern const FFCodec ff_libxavs_encoder;
 extern const FFCodec ff_libxavs2_encoder;
 extern const FFCodec ff_libxvid_encoder;
diff --git a/libavcodec/libxevd.c b/libavcodec/libxevd.c
new file mode 100644
index 0000000000..2e02176606
--- /dev/null
+++ b/libavcodec/libxevd.c
@@ -0,0 +1,488 @@ 
+/*
+ * libxevd decoder
+ * EVC (MPEG-5 Essential Video Coding) decoding using XEVD MPEG-5 EVC decoder library
+ *
+ * Copyright (C) 2021 Dawid Kozinski <d.kozinski@samsung.com>
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <float.h>
+#include <stdlib.h>
+
+#include <xevd.h>
+
+#include "libavutil/internal.h"
+#include "libavutil/common.h"
+#include "libavutil/opt.h"
+#include "libavutil/pixdesc.h"
+#include "libavutil/pixfmt.h"
+#include "libavutil/imgutils.h"
+#include "libavutil/cpu.h"
+
+#include "avcodec.h"
+#include "internal.h"
+#include "packet_internal.h"
+#include "codec_internal.h"
+#include "profiles.h"
+#include "decode.h"
+
+#define XEVD_PARAM_BAD_NAME -1
+#define XEVD_PARAM_BAD_VALUE -2
+
+#define EVC_NAL_HEADER_SIZE 2 /* byte */
+
+/**
+ * The structure stores all the states associated with the instance of Xeve MPEG-5 EVC decoder
+ */
+typedef struct XevdContext {
+    const AVClass *class;
+
+    XEVD id;            // XEVD instance identifier @see xevd.h
+    XEVD_CDSC cdsc;     // decoding parameters @see xevd.h
+    
+    // If end of stream occurs it is required "flushing" (aka draining) the codec,
+    // as the codec might buffer multiple frames or packets internally.
+    int draining_mode; // The flag is set if codec enters draining mode.
+} XevdContext;
+
+/**
+ * The function populates the XEVD_CDSC structure.
+ * XEVD_CDSC contains all decoder parameters that should be initialized before its use.
+ *
+ * @param[in] avctx codec context
+ * @param[out] cdsc contains all decoder parameters that should be initialized before its use
+ *
+ */
+static void get_conf(AVCodecContext *avctx, XEVD_CDSC *cdsc)
+{
+    int cpu_count = av_cpu_count();
+
+    /* clear XEVS_CDSC structure */
+    memset(cdsc, 0, sizeof(XEVD_CDSC));
+
+    /* init XEVD_CDSC */
+    if (avctx->thread_count <= 0)
+        cdsc->threads = (cpu_count < XEVD_MAX_TASK_CNT) ? cpu_count : XEVD_MAX_TASK_CNT;
+    else if (avctx->thread_count > XEVD_MAX_TASK_CNT)
+        cdsc->threads = XEVD_MAX_TASK_CNT;
+    else
+        cdsc->threads = avctx->thread_count;
+}
+
+/**
+ * Read NAL unit length
+ * @param bs input data (bitstream)
+ * @return the length of NAL unit on success, 0 value on failure
+ */
+static uint32_t read_nal_unit_length(const uint8_t *bs, int bs_size, AVCodecContext *avctx)
+{
+    uint32_t len = 0;
+    XEVD_INFO info;
+    int ret;
+
+    if (bs_size == XEVD_NAL_UNIT_LENGTH_BYTE) {
+        ret = xevd_info((void *)bs, XEVD_NAL_UNIT_LENGTH_BYTE, 1, &info);
+        if (XEVD_FAILED(ret)) {
+            av_log(avctx, AV_LOG_ERROR, "Cannot get bitstream information\n");
+            return 0;
+        }
+        len = info.nalu_len;
+        if (len == 0) {
+            av_log(avctx, AV_LOG_ERROR, "Invalid bitstream size! [%d]\n", bs_size);
+            return 0;
+        }
+    }
+
+    return len;
+}
+
+/**
+ * @param[in] xectx the structure that stores all the state associated with the instance of Xeve MPEG-5 EVC decoder
+ * @param[out] avctx codec context
+ * @return 0 on success, negative value on failure
+ */
+static int export_stream_params(const XevdContext *xectx, AVCodecContext *avctx)
+{
+    int ret;
+    int size;
+    int color_space;
+
+    avctx->pix_fmt = AV_PIX_FMT_YUV420P10;
+
+    size = 4;
+    ret = xevd_config(xectx->id, XEVD_CFG_GET_CODED_WIDTH, &avctx->coded_width, &size);
+    if (XEVD_FAILED(ret)) {
+        av_log(avctx, AV_LOG_ERROR, "Failed to get coded_width\n");
+        return AVERROR_EXTERNAL;
+    }
+
+    ret = xevd_config(xectx->id, XEVD_CFG_GET_CODED_HEIGHT, &avctx->coded_height, &size);
+    if (XEVD_FAILED(ret)) {
+        av_log(avctx, AV_LOG_ERROR, "Failed to get coded_height\n");
+        return AVERROR_EXTERNAL;
+    }
+
+    ret = xevd_config(xectx->id, XEVD_CFG_GET_WIDTH, &avctx->width, &size);
+    if (XEVD_FAILED(ret)) {
+        av_log(avctx, AV_LOG_ERROR, "Failed to get width\n");
+        return AVERROR_EXTERNAL;
+    }
+
+    ret = xevd_config(xectx->id, XEVD_CFG_GET_HEIGHT, &avctx->height, &size);
+    if (XEVD_FAILED(ret)) {
+        av_log(avctx, AV_LOG_ERROR, "Failed to get height\n");
+        return AVERROR_EXTERNAL;
+    }
+
+    ret = xevd_config(xectx->id, XEVD_CFG_GET_COLOR_SPACE, &color_space, &size);
+    if (XEVD_FAILED(ret)) {
+        av_log(avctx, AV_LOG_ERROR, "Failed to get color_space\n");
+        return AVERROR_EXTERNAL;
+    }
+    switch(color_space) {
+    case XEVD_CS_YCBCR400_10LE:
+        avctx->pix_fmt = AV_PIX_FMT_GRAY10LE;
+        break;
+    case XEVD_CS_YCBCR420_10LE:
+        avctx->pix_fmt = AV_PIX_FMT_YUV420P10LE;
+        break;
+    case XEVD_CS_YCBCR422_10LE:
+        avctx->pix_fmt = AV_PIX_FMT_YUV422P10LE;
+        break;
+    case XEVD_CS_YCBCR444_10LE:
+        avctx->pix_fmt = AV_PIX_FMT_YUV444P10LE;
+        break;
+    default:
+        av_log(avctx, AV_LOG_ERROR, "Unknown color space\n");
+        avctx->pix_fmt = AV_PIX_FMT_NONE;
+        return AVERROR_INVALIDDATA;
+    }
+
+    // the function returns sps->num_reorder_pics
+    ret = xevd_config(xectx->id, XEVD_CFG_GET_MAX_CODING_DELAY, &avctx->max_b_frames, &size);
+    if (XEVD_FAILED(ret)) {
+        av_log(avctx, AV_LOG_ERROR, "Failed to get max_coding_delay\n");
+        return AVERROR_EXTERNAL;
+    }
+
+    avctx->has_b_frames = (avctx->max_b_frames) ? 1 : 0;
+
+    return 0;
+}
+
+/**
+ * @brief Copy image in imgb to frame.
+ *
+ * @param avctx codec context
+ * @param[in] imgb
+ * @param[out] frame
+ * @return 0 on success, negative value on failure
+ */
+static int libxevd_image_copy(struct AVCodecContext *avctx, XEVD_IMGB *imgb, struct AVFrame *frame)
+{
+    int ret;
+    if (imgb->cs != XEVD_CS_YCBCR420_10LE) {
+        av_log(avctx, AV_LOG_ERROR, "Not supported pixel format: %s\n", av_get_pix_fmt_name(avctx->pix_fmt));
+        return AVERROR_INVALIDDATA;
+    }
+
+    if (imgb->w[0] != avctx->width || imgb->h[0] != avctx->height) { // stream resolution changed
+        if (ff_set_dimensions(avctx, imgb->w[0], imgb->h[0]) < 0) {
+            av_log(avctx, AV_LOG_ERROR, "Cannot set new dimension\n");
+            return AVERROR_INVALIDDATA;
+        }
+    }
+
+    if (ret = ff_get_buffer(avctx, frame, 0) < 0)
+        return ret;
+
+    av_image_copy(frame->data, frame->linesize, (const uint8_t **)imgb->a,
+                  imgb->s, avctx->pix_fmt,
+                  imgb->w[0], imgb->h[0]);
+
+    return 0;
+}
+
+/**
+ * Initialize decoder
+ * Create a decoder instance and allocate all the needed resources
+ *
+ * @param avctx codec context
+ * @return 0 on success, negative error code on failure
+ */
+static av_cold int libxevd_init(AVCodecContext *avctx)
+{
+    XevdContext *xectx = avctx->priv_data;
+    XEVD_CDSC *cdsc = &(xectx->cdsc);
+
+    /* read configurations and set values for created descriptor (XEVD_CDSC) */
+    get_conf(avctx, cdsc);
+
+    /* create decoder */
+    xectx->id = xevd_create(&(xectx->cdsc), NULL);
+    if (xectx->id == NULL) {
+        av_log(avctx, AV_LOG_ERROR, "Cannot create XEVD encoder\n");
+        return AVERROR_EXTERNAL;
+    }
+
+    xectx->draining_mode = 0;
+
+    return 0;
+}
+
+/**
+  * Decode frame with decoupled packet/frame dataflow
+  *
+  * @param avctx codec context
+  * @param[out] frame decoded frame
+  *
+  * @return 0 on success, negative error code on failure
+  */
+static int libxevd_receive_frame(AVCodecContext *avctx, AVFrame *frame)
+{
+    XevdContext *xectx = NULL;
+    AVPacket *pkt = NULL;
+    XEVD_IMGB *imgb = NULL;
+
+    int xevd_ret = 0;
+    int ret = 0;
+
+    xectx = avctx->priv_data;
+
+    pkt = av_packet_alloc();
+    if (!pkt)
+        return AVERROR(ENOMEM);
+
+    // obtain input data
+    ret = ff_decode_get_packet(avctx, pkt);
+    if (ret < 0 && ret != AVERROR_EOF) {
+        av_packet_free(&pkt);
+        return ret;
+    } else if(ret == AVERROR_EOF && xectx->draining_mode == 0) { // End of stream situations. Enter draining mode
+        
+        frame = NULL;
+        xectx->draining_mode = 1;
+
+        av_packet_free(&pkt);
+
+        return AVERROR_EOF;
+    }
+
+    if (pkt->size > 0) {
+        int bs_read_pos = 0;
+        XEVD_STAT stat;
+        XEVD_BITB bitb;
+        int nalu_size;
+
+        imgb = NULL;
+
+        while(pkt->size > (bs_read_pos + XEVD_NAL_UNIT_LENGTH_BYTE)) {
+            memset(&stat, 0, sizeof(XEVD_STAT));
+
+            nalu_size = read_nal_unit_length(pkt->data + bs_read_pos, XEVD_NAL_UNIT_LENGTH_BYTE, avctx);
+            if (nalu_size == 0) {
+                av_log(avctx, AV_LOG_ERROR, "Invalid bitstream\n");
+                av_packet_free(&pkt);
+                ret = AVERROR_INVALIDDATA;
+                return ret;
+            }
+            bs_read_pos += XEVD_NAL_UNIT_LENGTH_BYTE;
+
+            bitb.addr = pkt->data + bs_read_pos;
+            bitb.ssize = nalu_size;
+
+            /* main decoding block */
+            xevd_ret = xevd_decode(xectx->id, &bitb, &stat);
+            if (XEVD_FAILED(xevd_ret)) {
+                av_log(avctx, AV_LOG_ERROR, "Failed to decode bitstream\n");
+                av_packet_free(&pkt);
+                ret = AVERROR_EXTERNAL;
+                return ret;
+            }
+
+            bs_read_pos += nalu_size;
+
+            if (stat.nalu_type == XEVD_NUT_SPS) { // EVC stream parameters changed
+                if ((ret = export_stream_params(xectx, avctx)) != 0) {
+                    av_log(avctx, AV_LOG_ERROR, "Failed to export stream params\n");
+                    av_packet_free(&pkt);
+                    return ret;
+                }
+            }
+            if (stat.read != nalu_size)
+                av_log(avctx, AV_LOG_INFO, "Different reading of bitstream (in:%d, read:%d)\n,", nalu_size, stat.read);
+            if (stat.fnum >= 0) {
+                // already has a decoded image
+                if (imgb) {
+                    // xevd_pull uses pool of objects of type XEVD_IMGB.
+                    // The pool size is equal MAX_PB_SIZE (26), so release object when it is no more needed
+                    imgb->release(imgb);
+                    imgb = NULL;
+                }
+                xevd_ret = xevd_pull(xectx->id, &imgb);
+                if (XEVD_FAILED(xevd_ret)) {
+                    av_log(avctx, AV_LOG_ERROR, "Failed to pull the decoded image (xevd error code: %d, frame#=%d)\n", xevd_ret, stat.fnum);
+                    ret = AVERROR_EXTERNAL;
+                    av_packet_free(&pkt);
+
+                    return ret;
+                }  else if (xevd_ret == XEVD_OK_FRM_DELAYED) {
+                    if (imgb) {
+                        // xevd_pull uses pool of objects of type XEVD_IMGB.
+                        // The pool size is equal MAX_PB_SIZE (26), so release object when it is no more needed
+                        imgb->release(imgb);
+                        imgb = NULL;
+                    }
+                    av_packet_free(&pkt);
+
+                    return AVERROR(EAGAIN);
+                }
+                if (imgb) { // got frame
+                    int ret = libxevd_image_copy(avctx, imgb, frame);
+                    if(ret < 0) {
+                        av_log(avctx, AV_LOG_ERROR, "Image copying error\n");
+                        if (imgb) {
+                            imgb->release(imgb);
+                            imgb = NULL;
+                        }
+                        av_packet_free(&pkt);
+
+                        return ret;
+                    }
+
+                    // use ff_decode_frame_props() to fill frame properties
+                    ret = ff_decode_frame_props(avctx, frame);
+                    if (ret < 0) {
+                        if (imgb) {
+                            imgb->release(imgb);
+                            imgb = NULL;
+                        }
+                        av_packet_free(&pkt);
+                        av_frame_unref(frame);
+
+                        return ret;
+                    }
+                    // match timestamps and packet size
+                    ret = ff_decode_frame_props_from_pkt(avctx, frame, pkt);
+                    pkt->opaque = NULL;
+                    if (ret < 0) {
+                        if (imgb) {
+                            imgb->release(imgb);
+                            imgb = NULL;
+                        }
+                        av_packet_free(&pkt);
+                        av_frame_unref(frame);
+
+                        return ret;
+                    }
+                    
+                    frame->pkt_dts = pkt->dts;
+
+                    // xevd_pull uses pool of objects of type XEVD_IMGB.
+                    // The pool size is equal MAX_PB_SIZE (26), so release object when it is no more needed
+                    imgb->release(imgb);
+                    imgb = NULL;
+
+                    return 0;
+                } else
+                    return  AVERROR(EAGAIN);
+            }
+        }
+    } else { // decoder draining mode handling
+        xevd_ret = xevd_pull(xectx->id, &imgb);
+        if (xevd_ret == XEVD_ERR_UNEXPECTED)   // draining process completed
+            return AVERROR_EOF;
+        else if (XEVD_FAILED(xevd_ret)) {
+            av_log(avctx, AV_LOG_ERROR, "Failed to pull the decoded image (xevd error code: %d)\n", xevd_ret);
+
+            if (imgb) {
+                imgb->release(imgb);
+                imgb = NULL;
+            }
+
+            av_packet_free(&pkt);
+
+            return AVERROR_EXTERNAL;
+        }
+        if (imgb) { // got frame
+            int ret = libxevd_image_copy(avctx, imgb, frame);
+            if(ret < 0) {
+                if (imgb) {
+                    imgb->release(imgb);
+                    imgb = NULL;
+                }
+                av_packet_free(&pkt);
+            }
+
+            frame->pkt_dts = pkt->dts;
+
+            // xevd_pull uses pool of objects of type XEVD_IMGB.
+            // The pool size is equal MAX_PB_SIZE (26), so release object when it is no more needed
+            imgb->release(imgb);
+            imgb = NULL;
+
+            return 0;
+        }
+        return AVERROR_EOF;
+    }
+    return ret;
+}
+
+/**
+ * Destroy decoder
+ *
+ * @param avctx codec context
+ * @return 0 on success
+ */
+static av_cold int libxevd_close(AVCodecContext *avctx)
+{
+    XevdContext *xectx = avctx->priv_data;
+    if (xectx->id) {
+        xevd_delete(xectx->id);
+        xectx->id = NULL;
+    }
+    
+    xectx->draining_mode = 0;
+    
+    return 0;
+}
+
+#define OFFSET(x) offsetof(XevdContext, x)
+#define VD AV_OPT_FLAG_VIDEO_PARAM | AV_OPT_FLAG_DECODING_PARAM
+
+static const AVClass libxevd_class = {
+    .class_name = "libxevd",
+    .item_name  = av_default_item_name,
+    .version    = LIBAVUTIL_VERSION_INT,
+};
+
+const FFCodec ff_libxevd_decoder = {
+    .p.name             = "evc",
+    .p.long_name        = NULL_IF_CONFIG_SMALL("EVC / MPEG-5 Essential Video Coding (EVC)"),
+    .p.type             = AVMEDIA_TYPE_VIDEO,
+    .p.id               = AV_CODEC_ID_EVC,
+    .init               = libxevd_init,
+    FF_CODEC_RECEIVE_FRAME_CB(libxevd_receive_frame),
+    .close              = libxevd_close,
+    .priv_data_size     = sizeof(XevdContext),
+    .p.priv_class       = &libxevd_class,
+    .p.capabilities     = AV_CODEC_CAP_DELAY | AV_CODEC_CAP_OTHER_THREADS | AV_CODEC_CAP_AVOID_PROBING,
+    .p.profiles         = NULL_IF_CONFIG_SMALL(ff_evc_profiles),
+    .p.wrapper_name     = "libxevd",
+    .caps_internal      = FF_CODEC_CAP_INIT_CLEANUP | FF_CODEC_CAP_NOT_INIT_THREADSAFE | FF_CODEC_CAP_SETS_PKT_DTS | FF_CODEC_CAP_SETS_FRAME_PROPS
+};